SpringBoot Potential bug in Spring data; mapping null to wrapper class throws exception

Hi, I wanted to report a bug I noticed when upgrading Spring Boot 2.5.8 → 2.6.2. After the upgrade the Jdbc @Query when returning null it cannot be mapped to String, as before. Now we get an exception Couldn't find PersistentEntity for type class java.lang.String!.

java @Query("SELECT ST_AsGeoJson(ST_Envelope(ST_Union(polygon))) FROM tableName WHERE ...") String findBoundsForSectors();

Kind regards

Comment From: bclozel

I guess you're using Spring Data JDBC here? I don't think Spring Boot is involved here, could you report this to https://github.com/spring-projects/spring-data-jdbc/issues? If it turns out this is a Spring Boot problem after all, we can reopen this issue. Thanks!